Coating thickness measurement is an essential step in determining whether a coating system will perform to specifications. Color, gloss, adhesion, impact resistance, and other factors are all affected by paint thickness.
The PosiTector 6000 Coating Thickness Gage for all Metal Substrates is the Simple, Durable, and Accurate way to measure coating thickness.
When measuring paint thickness, it is important to never rely on a single reading. DFT, or dry film thickness, often varies across the surface, even at locations close to one another.
A statistical approach such as ISO 19840 is often specified to determine whether there is sufficient coating thickness to meet specifications. ISO 19840 mode on the PosiTector 6000 makes the process easy by performing all necessary calculations on the gage and creating pre-formatted reports with all required measurement data. Be sure to fully read and understand the ISO 19840 document prior to inspection.
ISO 19840 specifies the required number of readings depending on the size of the area to be measured in each Inspection area.
There are four key requirements for acceptance of an inspection area. The average of all the individual dry-film thicknesses must be equal to or greater than the NDFT. All individual dry-film thickness readings must be equal to or above 80% of the Nominal Dry Film Thickness, or NDFT. Individual dry-film thicknesses between 80% of the NDFT and the actual NDFT are acceptable provided that the number of these measurements is less than 20% of the total number individual measurements taken. Additionally, individual readings shall be less than or equal to the specified Maximum Dry Film Thickness.
Performed manually, the process can be confusing and requires several manual calculations. Using the ISO 19840 mode included with PosiTector 6000 Advanced models, an ISO 19840 inspection is easy.
First, ensure that the instrument is verified and adjusted for the substrate geometry. To learn more about getting started with the PosiTector 6000, view the video linked in the description.
Once the instrument is ready to measure, select “Memory” from the gage menu and choose “New 19840”.
Review and adjust the three parameters present, including NDFT, Max NDFT, and Minimum number of measurements, according to project specifications. Use the “up” and “down” buttons to move the highlighting bar and the “+” or “-” buttons to make adjustments to the selected parameter. If a maximum thickness value is not specified, ensure the MAX NDFT value is set to “0” and uncheck the “Use Max NDFT” box. Once all of the parameters are set, select “NEW” to create the batch.
Begin measuring, taking as many readings as specified in the “Sampling Plan” for the particular inspection area. Per ISO 19840, measurements are to be taken randomly across the surface. A “check-mark” or “X” will indicate whether the individual measurements passed or failed based on batch specifications.
If an individual measurement is not equal to or greater than 80% of the NDFT or is greater than or equal to the maximum specified DFT, the reading can be repeated by pressing the “-” button.
Take a repeat measurement within 10mm of the original measurement location. If the repeat measurement still does not meet the criteria, that measurement cannot be deleted and retaken. The maximum number of repeat measurements allowed in the batch is determined by the size of the inspection area.
Once the required readings for the first inspection area are taken, the user can press the “+” button create a duplicate ISO 19840 batch or close the batch by going into the “Memory” menu and selecting, “close”. If new specifications are required, a new 19840 batch will need to be created.
Once measurements have been saved, PosiSoft software makes it easy to manage data and create professional, custom reports. Simply connect your gage via USB or WiFi, to quickly import your readings, and save a PDF report. Information such as the gage calibration, calibration adjustments, individual measurements, calculated averages, and Pass/Fail conclusions will be presented.
Learn more about PosiSoft Software in the, “How to use PosiSoft Software for Better Coating Inspection” video.
Statistical approaches such as ISO 19840 provide more meaningful inspection data and are often required by job specifications and contracts.
The PosiTector 6000 Advanced coating thickness gage is the simple, durable, and accurate solution for DFT measurement on all metal substrates and is ideal for complying with ISO 19840. Backed by DeFelsko’s renowned quality, customer service, and exceptional two-year warranty, the PosiTector 6000 is the ideal choice for coating thickness measurement.
Visit www.defelsko.com/19840 to learn more.